Overhead shovel loader



Nov. 7, 1950 c. R. HOOVER 2,529,338 OVERHEAD sHovEL LoApERf Y VFiled March 11, 1946 Y l s sheetsshretl v v Curz'sfggoye?? @mmmwjwm vNov.` 7, 1950 Y vc.R.H`oovE1=zv Q 2,529,338

ovERHruuav sHovEL LOADER Filed aaron 11, 194e y :s sheets-sheet s 25 JSE .1552 434 es l J@ Patented Nov. 7, 1950 UNITED 'STATES PATENT OFFICE OVERHEAD SHOVEL LOADER Curtis R. Hoover, Edmondton, Alberta., Canada Application March 1l, 1946, Serial No. 653,589

10 Claims. (Cl. 214-131) scoop through an overhead arcuate path to an` intermediate transport position in which the tractor or other mobile scoop carrier may be driven toa desired position at which the load is to be dumped, whereupon the arcuate travel of the scoop is resumed from overhead transport position to a lowered dumping position, the scoop be- I ing restored thereafter by reverse travel through said arcuate path to fully lowered loading position in which it may again be driven into the earth or other material to be loaded.

One of the important objects of the invention is the provision of a mechanical movement in the nature of a compound lever system for eiectuating the overhead or arcuate travel of the scoop at substantially uniform velocity or angular displacement with an approximately constant loading on the driving or scoop-moving means.

Another object is the provision of a simpllied actuating mechanism for a scoop of the class described characterized principally by the fact that it can be operated from a single source of driving power, for example, a single hydraulic ram.

Still another object is the provision of a scoopactuating mechanism in the nature of a compound lever system and a single source of driving effort contrived to swing the scoop through its path of movement in a manner affording positive ycontrol by the voperator at all times and in all positions of the scoop with substantially uniform stability of the loaded scoop relative to the tractor or other vehicle upon which it is mounted.

Additional objects and aspects of novelty and utility relate to details of construction and operation of the preferred illustrative embodiment described hereinafter, and including particularly a scoop-operating means in the nature of a compound lever system comprising a fulcrum-mounted member which is directly connected to the hydraulic ram or other driving agency, and which is adapted to be displaced bodily and angularly by the latter, together with certain linkages cooperating with the said member to effect angular motion thereof and arcuate travel of the scoop, in a manner which will appear as the following description proceeds in view of the annexed drawings in which:

Fig. 1 is a side elevation of a crawler type tractor equipped with a dezer-loader type of scoop embodying the novel scoop-operating mechanism; the scoop is shown in loading position;

Fig. 2 is a 'view similar to that of Fig. 1 but showing the scoop in partially elevated position; Fig. 3 is a view similar to that of Fig. 1 but showing the scoop elevated to the overhead or transport position;

Fig. 4 is a view similar to that of Fig. 1 but showing the scoop in dumping position;

Fig. 5 is a.y top plan view, to enlarged scale, of the tractor and scoop mechanism showing particularly the duplication of actuating and driving means on opposite sides of the tractor, the scoop being in lowered or loading position;

Fig. 6 is a fragmentary perspective view, to enlarged scale, of the fulcrum-mounted member or translatory lever employed in the novel compound lever system for actuating the scoop.

Various types of overhead loaders are known in the art, many of them, however, being impractical because of dangers involved in their operation owing to instability and shifting of the center of gravity or dynamic balance, or because of the large amount of power required to operate them, or because of complicated and costly mechanism involved in procuring a safe, trouble-free device capable of economical operation and standing up under the extreme abuses and operating stresses to which machines of this class are exposed.

In my co-pending application Serial No. 589,313, filed April 20, 1945, now Patent No. 2,427,968 granted September 23, 1947 for a Powered Implement Carrier and Loader, I disclose an improved form of dozer-loader which is characterized by stable, reliable and relatively economical operation with a great reserve of operating power, and at the saine time a relatively simple construction commensurate with its ruggedness and dependability. This latter device, however, depends in part for its successful performance upon the use of several power units, e. g. two hydraulic rams, in effectuating the various movements of the scoop, and while this arrangement as disclosed and claimed in my said co-pending application is considered eminently satisfactory, the present invention eiects even further simplification and cost reduction by the provision of a scoop-actuating means, which is capable of performing all of the operations of the device of my said co-pending application with equal satisfaction, but which eliminates the need for more than one driving means or hydraulic unit.

for purposes of description only one side of the actual machine needs be described, whereas in fact the scoop-operating mechanism 'is duplicated on opposite sides of the tractor or other carrier; in other words, the illustrative views of Figs. 1 through 4 show the scoop mechanism on only one side of the tractor, while the duplicate operating mechanism actually employed are shown in the top plan view of Fig. 5; it will therefore be obvious to those skilled in the art that a complete working mechanism may be described with reference to only one side of the tractor as shown in Fig. l for example. Y

Referring to Fig. 1, the invention is illustrated in conjunction with a crawler type of tractor I including the usual power plant or motor II, operators seat I2, and articulated traction treads I3, it being understood, however, that the invention is applicable to any type of tractor or vehicle or to stationary installation, if desired.

The construction and disposition of the scoop is shown in greater detail in Fig. 5, wherein it will be observed that the scoop structure includes a bucket or shovel portion I extending across the front width of the tractor for attachment at opposite sides of the latter to a pair of yoke or boom arms IB and I1.

As in Fig` 1, the yoke or boom arms are pivotally supported in heavy brackets attached to the tractor on opposite sides thereof, the boom arm I1 having pivot connection I8, near its end remote from the scoop I5, in a heavy bracket I9. This bracket I9 has laterally-spaced inner and outer, similarly shaped, generally triangular side members I9a and I9b joined at their upper corner portions by a wide plate-like bridge 20, see Fig. 5. The outer side member I9a is attached at its lower region to the outer side of its associated truck frame 2l of the tractor whereas the inner side member |91) of the bracket is similarly attached to the inner side of said truck frame. In this manner the bracket is mounted so as to straddle the upper iiight of the associated track and provide clearance therefor beneath the bridging portion 20. Pivot pin I8 extends between and is mounted in both sides I9a and I9b of the track frame bracket, at an elevation between the upper and lower flights of the endless tread or track I3. It ls again to be understood that the foregoing construction, described with reference to one side of the tractor, as in Fig. 1, is duplicated on the opposite side of the tractor, as shown in Fig. 5.

Pivotally connected, as at 22, to the boom I'I between the pivoted end and scoop portion thereof, is a load link 23 having its opposite end pivotally connected at 24 to an arm 25 of an oddly shaped compound lever structure, shown in perries the two arms 25 and 21 upon opposite end portions projecting outwardly from opposite ends of a long bearing 30 extending laterally from the upper end of a translating link 3 I. The outer end of lever arm 2l is pivotally connected at 32 to an end of an anchoring link 33 while the opposite end of this link is pivotally connected to the inner side I9b of the associated track-framemounted bracket I9 at 34. The lower end of translaling link 3| is bifurcated as shown in Fig. 5 to straddle the free end portion of boom member Il for pivotal connection with the pivot I8 of the latter.

Means for swinging .the yoke and scoop includes two identical ram devices each comprising a cylinder 40 disposed between the two sides I9a and I9b of its associated bracket I9 and rockably supported by trunnions 4I in such bracket sides. A piston rod 42 of each device is pivotally connected at 43 with a pair of apertured ears 44 formed integrally with the bearing 30 on the link 3 I.

It is believed the operating characteristics of the apparatus will be understood best from the following description of its operation. In Fig. 1 the apparatus is shown with its various parts in the positions occupied when the scoop l5 is in a lowered position at the front of the vehicle. Fig. 1 illustrates a typical lowered position of the scoop where the latter is slightly above the ground level, although it is possible to adjust the apparatus for placing the scoop still lower. While the apparatus is conditioned as illustrated in Fig. 1, the vehicle may be driven forwardly for loading the scoop. Subsequent to this loading operation, the operator of the tractor can cause the introduction of pressure fluid, preferably oil, ,into the front ends of the cylinders 40 whereby the piston rods 42 of these cylinders will be forced rearwardly. Force is thus exerted against the upper end of each translating link 3I through thepins 43 in the ears 44 carried by the transversely extended bearings 30 on the upper ends of these links. In this manner the links 3I are caused to pivot counter-clockwise. The translatory pivotable structures 26 are thereby translated rearwardly transversely of the pivotal axes at I8 for the links 3I. During this rearward translaiory movement of the pivotable structures 26, pivoting of these structures upon their pivot pins 29 is controlled by the anchorage links 33. These anchorage links 33 prevent clockwise pivoting of the pivotable structures 26 about their pivots 29 so that the arms 25 of these structures are effective through the links 23 for pulling the booms I6 and I1 together with the scoop I5 upwardly. In fact, the anchorage links 33 have their pivotal connections 34 with the vehicle so spaced from the pivot pins I8 for their links 3l that the pivotal structures 26 actually pivot counter-clockwise during their translatory motion and thereby cause the outer end portions of the arms 25 to move at a greater angular velocity about the pivotal connections I8 than the angular velocity at which the links 3| move about these axes. In this manner the booms carrying the scoop are pivoted more rapidly than if the pivotable structures 26 were rigidly connectedl with the links 3l. Figs. 1, 2, 3 and 4 show progressive stages in moving the scoop from a lowered position in front of the vehicle to a dumping position rearwardly of the vehicle. Fig. 2 illustrates a position between the lowered position and a transport position shown in Fig. 3.

While uid is introduced into the front ends of the cylinders 40, pistons (not shown) in these cylinders and rigidly connected with the front ends of the piston rods 42 expel fluid from the front ends of the cylinders. iBy preventing both ingress and egress of uid from each end of the cylinders the piston and piston rods 42 can be hydraulically locked for maintaining the scoop in any selected position within its arc of travel. Thus while the scoop is in the transport position of Fig. 3, communication at both ends of the cylinders 40 can be terminated so that the booms or scoop-carrying yoke can be positively maintained in this upright position while the vehicle is backed up or otherwise driven to a place for dumping. Dumping is accomplished by the introduction of additional fluid into the frontY ends of the cylinders 40 to cause further translation" of the pivotable structures in a. rearward direction while these structures continue to be pivoted by the connections of the anchorage links 33 therewith. As the scoop approaches the position shown in Fig. 4 the material carried thereby will be poured therefrom over the edge which constitutes the upper edge, while in the Fig. 1 position.

Restoration of the scoop to the loaded position is accomplished by introducing fluid into the rear ends of the cylinders 40 upon expelling fluid from their front ends. In this manner the links 3| are forceably pivoted clockwise while the anchorage links 33 cause the pivotable structures 26 to be pivoted clockwise and cause the arms 25 thereof to move at a greater angular velocity than the links 3|.

The invention affords a scoop-actuating means of simplified construction which can be economically, safely, and reliably motivated by a single hydraulic or other power means, these and other advantages being achieved by contrivance of the novel linkage system including a translatory pivotable structure having three pivotal centers, a load link connected with one of those centers, an anchoring link connected with another of the centers, and a translating link connected with a third of the centers, whereby when the structure is displaced in a translatory or bodily sense it is also displaced in a rotative or pivotal sense,

The apparatus embodying this invention has the advantage of utilizing reasonably short links with reasonably short ranges of pivotal movement, whereby a single force-exerting means in the form of a trunnion-mounted hydraulic ram device operates each linkage with a favorable mechanical advantage throughout the operating range.

Having thus described a preferred form of the invention, with a view of clearly and concisely illustrating the same, I claim:

1. In an actuating mechanism operable by force received from a sing1e source to pivot a scoop boom of an overhead dozer loader, a frame, means pivotally mounting an end of the boom on said frame to accommodate swinging of the boom from a horizontal position upwardly to and beyond a vertical position, a lever structure, means supporting said lever structure on said frame for translation transversely of the pivotal `axis of said boom, means for applyingforce from said source to said lever structure to incur such translation thereof, means connecting said lever structure with the boom to pivot said boom incident to such translation, and means connected between said frame and the lever structure for constraining said lever structure for pivotal movement pursuant to such translation to modify the speed at which said boom ispivoted.

2. In a vehicular scoop loader, a scoop-carrying boom pivotally connected with the vehicle for swinging a scoop in a path reaching upwardly over the vehicle, a translating link disassociated with the pivotal connection of the boom with the vehicle and pivotally connected with the vehicle, means for pivoting said link, a lever structure pivotally on said link for translatory movement thereby when the lever is pivoted, a load link connecting said boom with a rst portion of said lever structure, an anchoring link pivotally connected with the vehicle at a point -out of, axial registry with the pivot connection of the translating link with the vehicle and reaching to pivotally connect with a second portion of said lever structure to causepivoting of the lever structure during the translation thereof.

3. In a vehicular scoop loader, a scoop-carrying boom pivotally connected with the vehicle for swinging a scoop in a path vreaching upwardly over the vehicle, a translating link disassciated with the pivotal connection of the boom with the vehicle and pivotally connected with the vehicle, means for` pivoting said link, a lever structu-re pivotally on said link for translatory movement thereby when the lever is pivoted, an anchoring link pivotally connected with the vehicle and with said lever structure to pivot said structure during its translation and thereby cause a portion of said structure to move at greater angular velocity than the translating link about the pivotal connection of the latter with the vehicle, and means connecting said portion of the lever structure with said boom to pivot the same pursuant to the translatory and pivotal motions of said structure.

4. A loader unit comprising a vehicle, a pair of booms pivoted on opposite sides of the vehicle on a common axis to facilitate the swinging of loadcarrying portions thereof in arcs, load-carrying means mounted on said load-carrying portions to be carried thereby upwardly and downwardly over the vehicle when the booms are pivoted, force exerting means, boom pivoting means actuatable by force received from said force exerting means to pivot said booms, said boom pivoting means including a structure which bodily translates during actuation of said boom pivoting means and which is pivotable during translation to increase the speed at which the booms are pivoted, and means for constraining movement of a portion of the structure to cause pivoting thereof pursuant to its translation.

5. In an overhead loader of the class described and including a pivoted scoop, actuating means for reversely swinging said scoop about its pivot, said means comprising a lever system including a structure translatorily movable concentrically of the pivot of the scoop, means mounting said structure for angular displacement about an axis intersecting the same, means for effecting translatory movement of said structure in reverse directions, link means drivingly connecting said structure with said scoop to constrain translation of a portion thereof and thereby cause swinging movement ofthe latter responsive to both translatory and angular movement of such structure, and link means pivotally connected with said structure and effecting said angular movement thereof responsive to translatory motion thereof.

6. Mechanism for swinging an overhead scoop, comprising: pivoted boom means for the scoop, a lever structure, link means pivotally connected with said structure to guide the latter in a predetermined arcuate path of bodily displacement, means pivotally connected with` said structure for causing rotative displacement thereof in addition to, and responsive to said bodily displacement thereof, reciprocable drive means for effecting reverse bodily displacements of said structure,

and pivoted link means connecting said structure with said boom means to cause swinging thereof in response to both bodily and rotative displacement of said structure.

7. In an overhead loader, a pivoted scoop-car- 7 rier, a lever structure connected with said scoopcarrier and movable about two centers of angular displacement to pivot said scoop-carrier, link means constraining said structure to revolve simultaneously about said centers responsive to thrust eiort thereon transversely of the axes of said centers, and hydraulic piston means applying thrust eiort to said structure as aforesaid in one direction.

8. In a loading machine, scoop means pivoted lto a part of said machine to swing overheadI reciprocatory drive means, a member having at least three principal pivotal centers in non-linear array but with axes of said centers extending in approximate parallelism, and a. plurality of links pivotally connected with said member at respective ones of said centers, one of said links being pivotally connected with the scoop means and the remaining links being pivotally connected to points ilxed relative to said machine part, means connecting said member with said drive means for reverse displacement by the latter to effect reverse overhead swinging of the scoop means responsive to complex revolving motion incurred by said member under the restraint of said remaining links.

9. Compound linkage mechanism for drivingly connecting an arcuately movable dozer-loader scoop structure with a reciprocable piston member, said linkage mechanism comprising: alever structure having pivotal centers in triangular array, a connection between said structure and said piston member for transmitting reciprocatory motion of said piston to said structure in a direction generally normal to the axes of said centers whereby to eiect reverse bodily motion of said structure, means connected with a first one of said centers conilning said reverse bodily motion of the structure to an arcuate path approximately concentric of the movement of said scoop structure, means connected with a second one of said centers effecting rotative motion of said structure responsive to bodily movement thereof as aforesaid, and means connected with a third one of said centers and said scoop structure for swinging the latter arcuately responsive to movement of the structure by the piston member as aforesaid.

10. Apparatus of the class described including a pivoted yoke, a scoop carried by said yoke. hydraulically reciprocative piston means for pivoting said yoke reversely, and compound linkage mechanism drivingly interconnecting said piston means and said yoke for movement of the latter by the former as aforesaid, said linkage mechanism comprising a. lever structure displaced lbodily by said piston means and linked with said yoke to pivot the latter responsive to bodily displacement of said structure, together with link means imparting additional and secondary angular displacement to said structure during said bodily displacement thereof, whereby a complex motion is imparted to said structure by action of said piston means for moving said yoke and scoop under predetermined conditions of mechanical advantage in said linkage mechanism determined by the relative magnitudes of said bodily and secondary displacements.

CURTIS R. HOOVER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

